code-review

code-review

Review a code change with two lenses: correctness (does it do what the PRD says?) and simplification (could it do the same with less?).

When to use

• A workflow invokes polymath-engineering:code-review after feature-dev.
• The user says "review this", "look this over", "what would you change?".

Inputs

• The diff under review (typically the current git diff or the file set from feature-dev).
• PRD + acceptance criteria for the change (preferred).
• Project conventions.

Procedure

1. Read the PRD's acceptance criteria. Each criterion is a checkpoint the code must satisfy.
2. Read the diff in dependency order (config → models → core logic → API → UI).
3. For each acceptance criterion, verify a test exists that would fail if the corresponding code were broken. If not, flag as a missing test.
4. Correctness pass:
   • Off-by-one, signedness, encoding, time-zone.
   • Concurrency: races, ordering, atomicity.
   • Error paths: do they leave the system in a recoverable state?
   • Boundary: empty input, single element, max input.
5. Simplification pass:
   • Could two functions be one? (Only if one of them has no other caller.)
   • Are there unused parameters, branches, or imports?
   • Are abstractions premature?
   • Are comments restating what the code already says?
6. Security smell check:
   • User input directly in SQL, HTML, shell, paths.
   • Secrets in code or logs.
   • Missing AuthN / AuthZ on new endpoints.
7. Test smell check:
   • Tests asserting implementation details.
   • Tests that pass without the code change (mock theater).
   • Flaky test patterns (sleeps, time-of-day).

Output

Structured summary keyed to the diff:

Acceptance criteria coverage:
  - AC1: PASS — test at <file>:<line>
  - AC2: MISSING — no test for refund path

Correctness findings:
  - <file>:<line> — boundary: rate-limit window misses requests exactly at start

Simplification findings:
  - <file>:<line> — extracted helper has one caller; inline it

Security findings:
  - <file>:<line> — user-supplied path concatenated without normalization

Test smell findings:
  - <file>:<line> — assertion checks private member rather than observed behavior

No emoji, no praise filler. Findings only.

Quality bar

• Every finding cites file:line.
• Every "MISSING" finding either nominates a missing test or proposes an alternative way to verify.
• No nit-style comments mixed in with correctness findings.